Adsorption and reaction of carbon monoxide at low temperature over a copper/ceria CO-PROX structured catalyst

CO reactive adsorption on a cordierite monolith washcoated with nanometric CuO/CeO2 has been studied at low temperature by following the time evolution of CO and CO2 concentration. The effect of adsorption time length, gas phase composition (H2 or O2 addition), temperature and contact time has been investigated. Results show that the large availability of surface and labile oxygen, related to the nature of nanometric ceria, allows for CO oxidation and CO2 release at room temperature. Tests under transient conditions show that i) interfacial copper/ceria sites re-oxidation can benefit of oxygen transfer from ceria, ii) hydroxyl groups, improving CO2 production rate, can be formed over the catalyst surface by reaction with molecular H2 at temperature above 80°C, iii) several CO and CO2 adsorbed species exist not only copper but also ceria sites, not all involved in the reaction pathway. Finally, the results represent a basis for developing a novel strategy for CO removal based on low temperature CO trap.